function esNumero(e) {
    k = (document.all) ? e.keyCode : e.which;
    if (k==8 || k==0) return true;
    patron = /[0-9]/;
    n = String.fromCharCode(k);
    return patron.test(n);
}
    
function esMontoNumerico(e) {
    k = (document.all) ? e.keyCode : e.which;
    if (k==8 || k==0) return true;
    patron = /[0-9.]/;
    n = String.fromCharCode(k);
    return patron.test(n);
}

function esFecha(e) {
    k = (document.all) ? e.keyCode : e.which;
    if (k==8 || k==0) return true;
    patron = /[0-9\/]/;
    n = String.fromCharCode(k);
    return patron.test(n);
}
